Children learn at a very early age that open doors lead either to unexplored rooms or the great outdoors. As soon as they observe an adult opening a door by manipulation of a doorknob, they attempt to do the same.
Very short children have even been observed to move a chair to a door, climb the chair and successfully open the door.
As a result of their urge to open doors and explore the spaces beyond, young children have wandered into busy streets, fallen down stairways and suffered other misfortunes a closed but unlocked door was intended to protect.
Inventors aware of the problem have developed several devices intended to prevent the facile turning of doorknobs by young children. For example, U.S. Pat. No. 2,781,220 to Zietlow discloses a mesh material forming a tubular length that is gathered by a drawstring that retains the material in position over a doorknob. U.S. Pat. No. 1,633,988 to Jones provides a doorknob cover made from a flexible, fabric material. U.S. Pat. No. 2,557,517 to Scruggs discloses a woven bag web having a draw cord. A plastic doorknob cover is shown in U.S. Pat. No. 2,587,285 to Broscoe. Other U.S. patents of interest include U.S. Pat. Nos. 2,610,877; 3,174,788; 4,007,956; 4,069,692 and 4,471,980.
All of the above devices make it at least slightly more difficult for children to turn doorknobs, but field tests have shown that even the best of them are routinely defeated, even by very young children.
There exists a clear need for an improved doorknob cover, but the prior art neither teaches nor suggests how a superior device could be provided.